:root{
  --paper:#f7f7f4;
  --panel:#ffffff;
  --ink:#171a21;
  --ink-soft:#565b66;
  --line:#e3e1da;
  --navy:#1f2a52;
  --navy-deep:#141c3d;
  --amber:#e0a234;
  --amber-deep:#b97f1e;
  --good:#2f7a4f;
  --bad:#b3452f;
  --radius:10px;
  --font-head:'Space Grotesk', system-ui, sans-serif;
  --font-body:'Inter', system-ui, sans-serif;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --paper:#14161c;--panel:#1c1f28;--ink:#eceef2;--ink-soft:#9aa0ac;--line:#2c2f39;
    --navy:#7c8ada;--navy-deep:#aeb8ec;--amber:#e8b458;--amber-deep:#f0c579;
  }
}
:root[data-theme="dark"]{
  --paper:#14161c;--panel:#1c1f28;--ink:#eceef2;--ink-soft:#9aa0ac;--line:#2c2f39;
  --navy:#7c8ada;--navy-deep:#aeb8ec;--amber:#e8b458;--amber-deep:#f0c579;
}

*{box-sizing:border-box;}
html,body{margin:0;padding:0;}
body{background:var(--paper);color:var(--ink);font-family:var(--font-body);line-height:1.6;-webkit-font-smoothing:antialiased;}
a{color:var(--navy);}
.wrap{max-width:960px;margin:0 auto;padding:0 20px;}
.wrap-narrow{max-width:760px;margin:0 auto;padding:0 20px;}

/* header / nav */
header.site{border-bottom:1px solid var(--line);padding:20px 0;position:sticky;top:0;background:var(--paper);z-index:10;}
header.site .bar{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:12px;max-width:960px;margin:0 auto;padding:0 20px;}
.brand{font-family:var(--font-head);font-weight:700;font-size:1.3rem;display:flex;align-items:center;gap:8px;text-decoration:none;color:var(--ink);}
.brand .mark{width:22px;height:22px;border-radius:6px;background:linear-gradient(135deg,var(--navy),var(--amber));display:inline-block;}
nav.top{display:flex;gap:18px;flex-wrap:wrap;}
nav.top a{color:var(--ink-soft);text-decoration:none;font-size:0.9rem;font-weight:600;}
nav.top a:hover, nav.top a.current{color:var(--navy);}

/* hero / page intro */
.hero{padding:40px 0 8px;}
.hero h1{font-family:var(--font-head);font-size:2rem;line-height:1.15;letter-spacing:-0.01em;margin:0 0 14px;max-width:20ch;}
.hero p.lede{color:var(--ink-soft);font-size:1.05rem;max-width:62ch;margin:0 0 8px;}
.breadcrumb{font-size:0.82rem;color:var(--ink-soft);margin:22px 0 4px;}
.breadcrumb a{color:var(--ink-soft);}

main{padding:8px 0 60px;}
h2{font-family:var(--font-head);font-size:1.25rem;margin:34px 0 12px;letter-spacing:-0.005em;}
h3{font-family:var(--font-head);font-size:1.02rem;margin:0 0 6px;}
p{margin:0 0 14px;}
ul{padding-left:20px;margin:0 0 14px;}
li{margin-bottom:6px;}

/* panel / tool card */
.panel{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:22px;margin:18px 0 30px;}

.dropzone{border:1.5px dashed var(--line);border-radius:var(--radius);padding:34px 20px;text-align:center;cursor:pointer;transition:border-color .15s ease, background .15s ease;}
.dropzone.drag{border-color:var(--navy);background:rgba(31,42,82,0.04);}
.dropzone strong{display:block;font-family:var(--font-head);font-size:1.05rem;margin-bottom:4px;}
.dropzone span{color:var(--ink-soft);font-size:0.9rem;}
.dropzone input{display:none;}

.row{display:flex;flex-wrap:wrap;gap:18px;align-items:flex-end;margin-top:18px;}
.field{display:flex;flex-direction:column;gap:6px;min-width:150px;}
.field label{font-size:0.82rem;font-weight:600;color:var(--ink-soft);}
.field input[type=number],.field input[type=text],.field select{border:1px solid var(--line);border-radius:7px;padding:9px 10px;background:var(--paper);color:var(--ink);font-family:var(--font-body);font-size:0.95rem;}
.field input[type=range]{width:180px;}

button.primary{appearance:none;border:none;border-radius:7px;background:var(--navy);color:#fff;font-family:var(--font-body);font-weight:600;font-size:0.95rem;padding:10px 20px;cursor:pointer;transition:background .15s ease, transform .1s ease;}
button.primary:hover{background:var(--navy-deep);}
button.primary:active{transform:translateY(1px);}
button.primary:disabled{opacity:0.5;cursor:not-allowed;}
button.ghost{appearance:none;border:1px solid var(--line);border-radius:7px;background:transparent;color:var(--ink);font-family:var(--font-body);font-weight:600;font-size:0.9rem;padding:9px 16px;cursor:pointer;}
button.ghost:hover{border-color:var(--ink-soft);}

.preview-grid{display:flex;flex-wrap:wrap;gap:16px;margin-top:20px;}
.preview-card{flex:1 1 220px;border:1px solid var(--line);border-radius:var(--radius);padding:14px;background:var(--paper);}
.preview-card h3{margin:0 0 10px;font-size:0.85rem;color:var(--ink-soft);font-weight:600;}
.preview-card img,.preview-card canvas{max-width:100%;border-radius:6px;display:block;background:repeating-conic-gradient(#00000010 0% 25%, transparent 0% 50%) 50% / 16px 16px;}

.status{font-size:0.88rem;color:var(--ink-soft);margin-top:10px;min-height:1.2em;}
.status.good{color:var(--good);}
.status.bad{color:var(--bad);}

.file-list{list-style:none;margin:16px 0 0;padding:0;display:flex;flex-direction:column;gap:8px;}
.file-list li{display:flex;align-items:center;justify-content:space-between;gap:10px;border:1px solid var(--line);border-radius:7px;padding:9px 12px;font-size:0.88rem;background:var(--paper);}
.file-list li button{background:none;border:none;color:var(--bad);cursor:pointer;font-size:0.85rem;font-weight:600;}

.download-link{display:inline-block;margin-top:14px;background:var(--amber);color:#241800;font-weight:700;font-family:var(--font-head);padding:10px 18px;border-radius:7px;text-decoration:none;font-size:0.92rem;}
.download-link:hover{background:var(--amber-deep);}

canvas#sigpad{width:100%;height:220px;border:1.5px dashed var(--line);border-radius:var(--radius);touch-action:none;cursor:crosshair;background:repeating-conic-gradient(#00000008 0% 25%, transparent 0% 50%) 50% / 18px 18px;}

.segmented{display:inline-flex;border:1px solid var(--line);border-radius:7px;overflow:hidden;}
.segmented button{border:none;background:var(--paper);color:var(--ink-soft);padding:8px 14px;font-size:0.85rem;font-weight:600;cursor:pointer;}
.segmented button.active{background:var(--navy);color:#fff;}

/* steps list */
ol.steps{list-style:none;counter-reset:step;padding:0;margin:0 0 14px;}
ol.steps li{counter-increment:step;position:relative;padding-left:38px;margin-bottom:16px;}
ol.steps li::before{content:counter(step);position:absolute;left:0;top:0;width:26px;height:26px;border-radius:50%;background:var(--navy);color:#fff;font-family:var(--font-head);font-size:0.82rem;font-weight:700;display:flex;align-items:center;justify-content:center;}

/* faq */
.faq-item{border-bottom:1px solid var(--line);padding:16px 0;}
.faq-item:last-child{border-bottom:none;}
.faq-item h3{font-family:var(--font-head);font-size:1rem;margin:0 0 6px;}
.faq-item p{color:var(--ink-soft);margin:0;}

/* related tools */
.related-tools{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:12px;margin:10px 0 30px;}
.related-tools a{display:block;border:1px solid var(--line);border-radius:var(--radius);padding:14px 16px;text-decoration:none;color:var(--ink);background:var(--panel);transition:border-color .15s ease;}
.related-tools a:hover{border-color:var(--navy);}
.related-tools a strong{display:block;font-family:var(--font-head);font-size:0.95rem;margin-bottom:4px;color:var(--ink);}
.related-tools a span{color:var(--ink-soft);font-size:0.85rem;}

/* ad slot */
.ad-slot{max-width:960px;margin:0 auto 30px;padding:0 20px;}
.ad-slot .box{border:1px dashed var(--line);border-radius:var(--radius);padding:18px;text-align:center;color:var(--ink-soft);font-size:0.8rem;}

/* footer */
footer{border-top:1px solid var(--line);padding:30px 0 40px;color:var(--ink-soft);font-size:0.85rem;}
footer .cols{display:flex;flex-wrap:wrap;gap:30px;margin-bottom:20px;}
footer .col h4{font-family:var(--font-head);font-size:0.85rem;color:var(--ink);margin:0 0 10px;}
footer .col a{display:block;color:var(--ink-soft);text-decoration:none;margin-bottom:7px;font-size:0.86rem;}
footer .col a:hover{color:var(--navy);}
footer .bottom-line{border-top:1px solid var(--line);padding-top:16px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;}

.note{background:var(--panel);border:1px solid var(--line);border-left:3px solid var(--amber);border-radius:8px;padding:14px 18px;font-size:0.9rem;color:var(--ink-soft);margin-bottom:26px;}

@media (max-width:640px){
  .row{gap:12px;}
  .hero h1{font-size:1.6rem;max-width:100%;}
}